<h3>
Answer:</h3>
89.88° C
<h3>
Explanation:</h3>
<u>We are given;</u>
- Mass of gold cylinder as 75 g
- specific heat of gold is 0.129 J/g°C
- Initial temperature of gold cylinder is 65°C
- Mass of water is 500 g
- Initial temperature of water is 90 °C
We are required to calculate the final temperature;
- We know that Quantity of heat is given by the product of mass, specific heat capacity and change in temperature.
<h3>Step 1: Calculate the quantity of heat absorbed by the Gold cylinder</h3>
Assuming the final temperature is X° C
Then; ΔT = (X-65)°C
Therefore;
Q = 75 g × 0.129 J/g°C × (X-65)°C
= 9.675X - 628.875 Joules
<h3>Step 2: Calculate the quantity of heat released by water</h3>
Taking the final temperature as X° C
Change in temperature, ΔT = (90 - X)° C
Specific heat capacity of water is 4.184 J/g°C
Therefore;
Q = 500 g × 4.184 J/g°C × (90 - X)° C
= 188,280 -2092X joules
<h3>Step 3: Calculate the final temperature, X°C</h3>
we know that the heat gained by gold cylinder is equal to the heat released by water.
9.675X - 628.875 Joules = 188,280 -2092X joules
2101.675 X = 188908.875
X = 89.88° C
Thus, the final temperature is 89.88° C
Answer:
It will take 3.3 s for [NOCl] to decrease to 0.042 M.
Explanation:
Integrated rate law for this second order reaction-
![\frac{1}{[NOCl]}=kt+\frac{1}{[NOCl]_{0}}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5BNOCl%5D%7D%3Dkt%2B%5Cfrac%7B1%7D%7B%5BNOCl%5D_%7B0%7D%7D)
where, [NOCl] is concentration of NOCl after "t" time, ![[NOCl]_{0}](https://tex.z-dn.net/?f=%5BNOCl%5D_%7B0%7D)
is initial concentration of NOCl and k is rate constant.
Here, = 0.076 M, k = 3.2 
and [NOCl] = 0.042 M
So, ![\frac{1}{0.042M}=[3.2M^{-1}s^{-1}\times t]+\frac{1}{0.076M}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B0.042M%7D%3D%5B3.2M%5E%7B-1%7Ds%5E%7B-1%7D%5Ctimes%20t%5D%2B%5Cfrac%7B1%7D%7B0.076M%7D)
or, t = 3.3 s
So, it will take 3.3 s for [NOCl] to decrease to 0.042 M.
<span>Most of the atom's mass and all of its positive charge is contained in a small core called the nucleus.</span>
